Saints Row the Third – The Full Package is on sale for $12.49 (75% off) at Amazon. Requires Steam activation. Also comes with a $5 credit for Saints Row IV ($60). Base Saints Row: The Third game is $8 (75% ff).
Saints Row 2 is on sale for $3.75 (75% off). Activates on Steam.
Party of Sin is on sale for $5 (50% off). Looks like you can purchase a Steam version or a non-Steam version.